14,055 research outputs found
Friendship prediction and homophily in social media
International audienceSocial media have attracted considerable attention because their open-ended nature allows users to create lightweight semantic scaffolding to organize and share content. To date, the interplay of the social and topical components of social media has been only partially explored. Here, we study the presence of homophily in three systems that combine tagging social media with online social networks. We find a substantial level of topical similarity among users who are close to each other in the social network. We introduce a null model that preserves user activity while removing local correlations, allowing us to disentangle the actual local similarity between users from statistical effects due to the assortative mixing of user activity and centrality in the social network. This analysis suggests that users with similar interests are more likely to be friends, and therefore topical similarity measures among users based solely on their annotation metadata should be predictive of social links. We test this hypothesis on several datasets, confirming that social networks constructed from topical similarity capture actual friendship accurately. When combined with topological features, topical similarity achieves a link prediction accuracy of about 92%
Folks in Folksonomies: Social Link Prediction from Shared Metadata
Web 2.0 applications have attracted a considerable amount of attention
because their open-ended nature allows users to create light-weight semantic
scaffolding to organize and share content. To date, the interplay of the social
and semantic components of social media has been only partially explored. Here
we focus on Flickr and Last.fm, two social media systems in which we can relate
the tagging activity of the users with an explicit representation of their
social network. We show that a substantial level of local lexical and topical
alignment is observable among users who lie close to each other in the social
network. We introduce a null model that preserves user activity while removing
local correlations, allowing us to disentangle the actual local alignment
between users from statistical effects due to the assortative mixing of user
activity and centrality in the social network. This analysis suggests that
users with similar topical interests are more likely to be friends, and
therefore semantic similarity measures among users based solely on their
annotation metadata should be predictive of social links. We test this
hypothesis on the Last.fm data set, confirming that the social network
constructed from semantic similarity captures actual friendship more accurately
than Last.fm's suggestions based on listening patterns.Comment: http://portal.acm.org/citation.cfm?doid=1718487.171852
Recommender Systems
The ongoing rapid expansion of the Internet greatly increases the necessity
of effective recommender systems for filtering the abundant information.
Extensive research for recommender systems is conducted by a broad range of
communities including social and computer scientists, physicists, and
interdisciplinary researchers. Despite substantial theoretical and practical
achievements, unification and comparison of different approaches are lacking,
which impedes further advances. In this article, we review recent developments
in recommender systems and discuss the major challenges. We compare and
evaluate available algorithms and examine their roles in the future
developments. In addition to algorithms, physical aspects are described to
illustrate macroscopic behavior of recommender systems. Potential impacts and
future directions are discussed. We emphasize that recommendation has a great
scientific depth and combines diverse research fields which makes it of
interests for physicists as well as interdisciplinary researchers.Comment: 97 pages, 20 figures (To appear in Physics Reports
Tag-Aware Recommender Systems: A State-of-the-art Survey
In the past decade, Social Tagging Systems have attracted increasing
attention from both physical and computer science communities. Besides the
underlying structure and dynamics of tagging systems, many efforts have been
addressed to unify tagging information to reveal user behaviors and
preferences, extract the latent semantic relations among items, make
recommendations, and so on. Specifically, this article summarizes recent
progress about tag-aware recommender systems, emphasizing on the contributions
from three mainstream perspectives and approaches: network-based methods,
tensor-based methods, and the topic-based methods. Finally, we outline some
other tag-related works and future challenges of tag-aware recommendation
algorithms.Comment: 19 pages, 3 figure
Link creation and profile alignment in the aNobii social network
The present work investigates the structural and dynamical properties of
aNobii\footnote{http://www.anobii.com/}, a social bookmarking system designed
for readers and book lovers. Users of aNobii provide information about their
library, reading interests and geographical location, and they can establish
typed social links to other users. Here, we perform an in-depth analysis of the
system's social network and its interplay with users' profiles. We describe the
relation of geographic and interest-based factors to social linking.
Furthermore, we perform a longitudinal analysis to investigate the interplay of
profile similarity and link creation in the social network, with a focus on
triangle closure. We report a reciprocal causal connection: profile similarity
of users drives the subsequent closure in the social network and, reciprocally,
closure in the social network induces subsequent profile alignment. Access to
the dynamics of the social network also allows us to measure quantitative
indicators of preferential linking.Comment: http://www.iisocialcom.org/conference/socialcom2010
Gravity Effects on Information Filtering and Network Evolving
In this paper, based on the gravity principle of classical physics, we
propose a tunable gravity-based model, which considers tag usage pattern to
weigh both the mass and distance of network nodes. We then apply this model in
solving the problems of information filtering and network evolving.
Experimental results on two real-world data sets, \emph{Del.icio.us} and
\emph{MovieLens}, show that it can not only enhance the algorithmic
performance, but can also better characterize the properties of real networks.
This work may shed some light on the in-depth understanding of the effect of
gravity model
"How May I Help You?": Modeling Twitter Customer Service Conversations Using Fine-Grained Dialogue Acts
Given the increasing popularity of customer service dialogue on Twitter,
analysis of conversation data is essential to understand trends in customer and
agent behavior for the purpose of automating customer service interactions. In
this work, we develop a novel taxonomy of fine-grained "dialogue acts"
frequently observed in customer service, showcasing acts that are more suited
to the domain than the more generic existing taxonomies. Using a sequential
SVM-HMM model, we model conversation flow, predicting the dialogue act of a
given turn in real-time. We characterize differences between customer and agent
behavior in Twitter customer service conversations, and investigate the effect
of testing our system on different customer service industries. Finally, we use
a data-driven approach to predict important conversation outcomes: customer
satisfaction, customer frustration, and overall problem resolution. We show
that the type and location of certain dialogue acts in a conversation have a
significant effect on the probability of desirable and undesirable outcomes,
and present actionable rules based on our findings. The patterns and rules we
derive can be used as guidelines for outcome-driven automated customer service
platforms.Comment: 13 pages, 6 figures, IUI 201
On social networks and collaborative recommendation
Social network systems, like last.fm, play a significant role in Web 2.0, containing large amounts of multimedia-enriched data that are enhanced both by explicit user-provided annotations and implicit aggregated feedback describing the personal preferences of each user. It is also a common tendency for these systems to encourage the creation of virtual networks among their users by allowing them to establish bonds of friendship and thus provide a novel and direct medium for the exchange of data.
We investigate the role of these additional relationships in developing a track recommendation system. Taking into account both the social annotation and friendships inherent in the social graph established among users, items and tags, we created a collaborative recommendation system that effectively adapts to the personal information needs of each user. We adopt the generic framework of Random Walk with Restarts in order to provide with a more natural and efficient way to represent social networks.
In this work we collected a representative enough portion of the music social network last.fm, capturing explicitly expressed bonds of friendship of the user as well as social tags. We performed a series of comparison experiments between the Random Walk with Restarts model and a user-based collaborative filtering method using the Pearson Correlation similarity. The results show that the graph model system benefits from the additional information embedded in social knowledge. In addition, the graph model outperforms the standard collaborative filtering method.</p
Topicality and Social Impact: Diverse Messages but Focused Messengers
Are users who comment on a variety of matters more likely to achieve high
influence than those who delve into one focused field? Do general Twitter
hashtags, such as #lol, tend to be more popular than novel ones, such as
#instantlyinlove? Questions like these demand a way to detect topics hidden
behind messages associated with an individual or a hashtag, and a gauge of
similarity among these topics. Here we develop such an approach to identify
clusters of similar hashtags by detecting communities in the hashtag
co-occurrence network. Then the topical diversity of a user's interests is
quantified by the entropy of her hashtags across different topic clusters. A
similar measure is applied to hashtags, based on co-occurring tags. We find
that high topical diversity of early adopters or co-occurring tags implies high
future popularity of hashtags. In contrast, low diversity helps an individual
accumulate social influence. In short, diverse messages and focused messengers
are more likely to gain impact.Comment: 9 pages, 7 figures, 6 table
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